A terahertz wave refers to electromagnetic wave radiation with a frequency band of 0.1-10 THz, and its electromagnetic wave spectrum is located between microwave and infrared bands. Therefore, a terahertz system takes into account the advantages of electronic and optical systems. After the development in recent years, the terahertz technology is gradually developed to nondestructive testing, security inspection, medicine, radar, communication, astronomy and other application fields.
At present, research on terahertz waves at home and abroad mainly focuses on the application of the terahertz wave technology, terahertz spectrum analysis and other fields, for example, research on optical properties of an ultra-thin metal film at a terahertz band, application of a terahertz band metamaterial in biosensing, application and research of the terahertz technology in a medical test box diagnosis, and so on. However, the evaluation, research, adjustment and correction of a terahertz wave system and other terahertz wave attenuators are rarely reported. At present, the adjustable terahertz wave attenuation devices used at home and abroad have very complex structures and are inconvenient to be compatible with other terahertz equipment.